988 resultados para Comunidades periféricas - Balsas (MA)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Foram amostrados 17 riachos, em 12 fragmentos durante a estação seca (junho a agosto de 2007 e de 2008). Foram identificadas 16 espécies de macroalgas, pertencentes a 14 gêneros. Cyanophyta e Chlorophyta foram os grupos mais representativos (44 e 38%, respectivamente), seguidos por Rhodophyta (12%) e Heterokontophyta (6%). O número global de espécies foi baixo, fato atribuído à predominância de substrato areno-argiloso (65%) e de trechos sombreados (53%). A maioria das espécies (69%) ocorreu exclusivamente em um único riacho, padrão frequentemente observado para macroalgas lóticas. Vaucheria pseudogeminata foi reportada pela primeira vez para o Brasil e Trichocoleus sociatus para a região noroeste do Estado de São Paulo. Comparando a flora de macroalgas encontrada com aquelas de outras regiões/biomas do Estado de São Paulo, notou-se maior semelhança com Floresta Tropical (56% espécies em comum), conforme esperado, por ser o bioma mais próximo e composto também por Floresta Estacional Semidecidual.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O presente trabalho de pesquisa teve como objetivo identificar a composição florística de comunidades de plantas daninhas presentes em áreas agrícolas de várzea, manejadas em diferentes sistemas. O trabalho foi desenvolvido em áreas de produção de arroz irrigado das cooperativas: Cooperativas Mista Rural Vale do Javaés e Cooperativa Agroindustrial Rio Formoso, em Formoso do Araguaia-TO. Foram separadas três áreas de 1 ha, sendo: 1 - área sem rotação de culturas (arroz/pousio) há mais de cinco anos; 2 - área com rotação de culturas (arroz/soja) há mais de cinco anos; 3 - área com rotação de culturas (arroz/melancia) há mais de dois anos. Para caracterização e estudo fitossociológico da comunidade infestante foi utilizado, como unidade amostral, um quadro (1,0 x 1,0 m), lançado aleatoriamente dentro da área de estudo (método do quadrado inventário), por meio de um caminhamento em ziguezague. Na área sem rotação, foram identificadas 8 famílias e 16 espécies, destacando-se a família Poaceae com maior número espécies; Fimbristylis miliacea (Cyperaceae) foi a espécie com o maior índice de importância relativa (84,46%). Na área com rotação arroz/soja, foram identificadas 8 famílias e 12 espécies, destacando-se as famílias Poaceae e Cyperaceae com maior número espécies; Cyperus esculentus (Cyperaceae) foi a espécie com o maior índice de importância relativa (91,4%). Na área com rotação arroz/melancia foram identificadas seis famílias e oito espécies, destacando-se as famílias Euphorbiaceae e Lamiaceae com maior número espécies; Physalis angulata (Solanaceae) foi a espécie com o maior índice de importância relativa (153,1%), seguida por Eclipta alba (Compositae) e Hyptis lophanta (Lamiaceae), com 40,45 e 37,6%, respectivamente.
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Objetivou-se com este trabalho caracterizar os produtores de bananeira 'Maçã' do município de Ribeirão do Sul/SP, quanto à tecnologia empregada no cultivo da frutífera e à produção obtida. A partir desta avaliação preliminar, pretendeu-se estabelecer algumas inferências com relação à incidência da doença Mal-do-Panamá e o diagnóstico nutricional das propriedades. Através dos questionários aplicados, bem como das análises foliares e de solo, detectou-se que os produtores realizam a prática da adubação e calagem sem resultados de análise de solo, não realizam análises foliares e que os teores de nutrientes no solo e nas folhas apresentam-se em níveis desbalanceados para muitas propriedades avaliadas. A incidência da doença Mal-do-Panamá foi considerada baixa ou ausente em 65% das propriedades avaliadas.
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We report on the use of dynamic scale theory and fractal analyses in the Study of distinct growth stages of layer-by-layer (LBL) films of poly(allylamine hydrochloride) (PAH) and a side-chain-substituted azobenzene copolymer (Ma-co-DR13). The LBL films were adsorbed oil glass substrates and characterized with atomic force microscopy with the Ma-co-DR13 at the top layer. The ganular morphology exhibited by the films allowed the observation of the growth process inside and outside the grains. The growth outside the grains was found to follow the Kardar-Parisi-Zhang model, with fractal dimensions of ca. 2.6. One could expect that inside the grains the morphology would be close to a Euclidian surface with fractal dimension of ca. 2 for any growth stage. The latter, however, was observed only for thicker films containing more than 10 bilayers. For thinner films the morphology was well described by a self-affine fractal. Such dependence of the growth behavior with the film thickness is associated with a more complete coverage of adsorption sites in thicker films due to diffusion of polymer molecules. (c) 2004 Elsevier B.V. All rights reserved.
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The Araes gold deposit, located in eastern Mato Grosso State, central Brazil, is hosted in Neoproterozoic volcanosedimentary rocks of the Paraguay belt, which formed during collision of the Amazonian craton and the Rio Apa block. Ar-40/Ar-39 geochronology and Pb and S isotopic analyses constrain the timing and sources of mineralization. Three biotite flakes from two samples of metavolcanic host rock yield Ar-40/Ar-39 plateau ages between 5941 and 531 Ma, interpreted as cooling ages following regional metamorphism. Clay minerals from a hydrothermal alteration zone yield an Ar-40/Ar-39 integrated age of 503 +/- 3 Ma. Galena grains from ore-bearing veins yield values of Pb-206/(204)pb from 17.952 to 18.383, Pb-207/Pb-204 from 15.156 to 15.811, and Pb-208/Pb-204 from 38.072 to 39.681. Pyrite grains from ore-bearing veins yield values of Pb-206/Pb-204 from 18.037 to 18.202, Pb-207/Pb-204 from 15.744 to 15.901., and Pb-208/(204)pb from 38.338 to 38.800. Pb isotope variations may be explained in terms of mixing a less radiogenic lead component (mu similar to 8.4) from mafic and ultramafic basement host-rocks (Nova Xavantina metavolcanosedimentary rocks) and a more radiogenic lead component (mu similar to 9.2) probably derived from supracrustal rocks (Cuiaba sedimentary groups). Sulfur isotope compositions are homogeneous, with delta S-34 values ranging from -1.1 parts per thousand to 0.9 parts per thousand (galena) and -0.7 parts per thousand to 0.9 parts per thousand (pyrite), suggesting a mantle-derived reservoir for the mineralizing solutions. Based on the Ar, Pb, and S isotope data, we suggest that the precious metals were remobilized from metavolcanic host rocks by hydrothermal solutions during Brasilide-Panafrican regional metamorphism. The Arabs gold deposit probably formed during a late stage of the orogeny, coeval with other mineralization events in the Paraguay Belt.
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Evaluation is regarded as a highly complex, continuous process intended to improve the object-subject involved. In the case of marginal metropolitan neighborhoods, whose inhabitants live in conditions unfit for human beings, we must remember that the specific actors in the drama - the users of the area of operation - should be the main creators of their own individual and community development through the evaluation-improvement process. This paper provides a basis for discussing such an approach. -from English summary
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The Araguaia-Tocantins geosuture, which separates the Araguaia Fold Belt (AFB) from the Archean Amazonian Craton, was active in the late Middle Proterozoic. The Baixo Araguaia Supergroup was deposited, consisting of the Estrondo Group (lower quartzites with intercalated schists), Xambioá Formation (schists), and Canto da Vazante Formation (upper feldspathic schists); and the Tocantins Group consisting of the Couto Magalhaës Formation (phyllites, quartzites, slates, limestones, and metacherts) and Pequizeiro Formation (upper chlorite schists); and associated mafic-ultramafic bodies. The deformational history includes four regional phases of deformation within this supracrustal sequence: recumbent folds with vergence to the west; refolding with a N-S trend; an intense crenulation episode; and late thrusting from east to west. Metamorphism is of intermediate or intermediate-high pressure type with garnet, biotite, chlorite, and sericite isograds succeeded by a slightly or non-metamorphosed zone, from east to west. Rocks surrounding sparse gneissic-cored domes contain isograds of staurolite, kyanite, and fibrolite. These isograds are believed to be associated with the 1100 Ma Uruaçuano event. The Brasiliano Orogeny strongly affected the AFB with displacements due to transcurrent reactivation of great and old faults of the basement, slight folding in the supracrustal sequence, intrusion of small granite bodies, and development of domes with associated normal faults. The area underlain by the Estrondo Group was uplifted at this time, causing the deposition of the Rio das Barreiras polymictic conglomerate of the central area. K-Ar and Rb-Sr analyses date this thermo-tectonic event at 550 ± 100 Ma. The Archean basement is exposed in the cores of domes as a granite-gneiss association, the Colméia complex, which shows thermo-tectonic features that may be interpreted as polycyclic imprints (Jequié, Transamazonian?, Uruaçuano, and Brasiliano Events). © 1989.
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Uranium-lead zircon ages between 660 and 640 Ma, obtained from a series of calc-alkaline orthogneisses and plutons in southeast Brazil's Central Mantiqueira Province, suggest that a significant period of magmatism occurred in this region prior to the collisional assembly of West Gondwana (presently constrained in the region between ca. 625 and 580 Ma). While the nature of this earlier magmatism is presently unclear, some preliminary Sm-Nd data suggest that these magmas were not solely derived from the Paleoproterozoic lithosphere, but appear to represent hybrid products of Paleoproterozoic and Neoproterozoic sources. As such hybrid mixtures have been most commonly observed in continental are settings, it is possible that the 660 to 640 Ma magmatism represents are magmatism that resulted from subduction of Neoproterozoic oceanic crust during early precollisional convergence and closure of a branch of either the Adamastor or Goianides oceans.
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The morphological, mechanical and rheological properties of nylon 6/acrylonitrile-butadiene-styrene blends compatibilized with MMA-MA [poly(methyl methacrylate-comaleic anhydride)] copolymers were studied. A twin screw extruder was used for melt-blended the polymers and the injection moulding process was used to mold the samples. The main focus was on nylon 6/ ABS blends compatibilized with one MMA-MA copolymer. This copolymer has PMMA segments that appear to be miscible with the styrene-acrylonitrile (SAN) phase of ABS and the anhydride groups can react with amine end groups of the nylon 6 (Ny6) to form graft copolymers at the interface between Ny6 and ABS rich phases. Tensile and impact and morphological properties were enhanced by the incorporation of this copolymer. Transmission electron microscopy (TEM) observations revealed that the ABS domains are finely dispersed in nylon 6 matrix and led to the lowest ductile-brittle transition temperatures and highest impact properties. It can be concluded that the MMA-MA copolymer is an efficient alternative for the reactive compatibilization and can be used as a compatibilizer for nylon 6/ABS blends.© 2003 Kluwer Academic Publishers.
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This study's goal was to caryy out an ethnobotanical survey focusing on the knowledge and use of medicinal plants within two rural communities (Marambaia and Camboinha), which are situated in an Environmental Protection Area in Atlantic Forest of Southern Bahia, Brazil. These communities use medicinal plants as an important therapeutic activity, which permits the rural inhabitants to be self-sufficient regarding health care. Data were collected through interviews with 26 families (24% of the total). The medicinal plants collected (98 species) were catalogued, identified and deposited at the Herbarium Rio Clarense (HRCB). They belong to 40 families so that Lamiaceae was the most cited. The majority of these species (78%) are cultivated, usually in backyards by local inhabitants. The leaf is the most common part of the plant used in medicinal preparations. The species with the greatest number of citations were Chenopodium ambrosioides L. and Lippia alba (Mill) N.E. Br. These species are also associated with the highest number of therapeutic uses. Use agreement and diversity index from this survey were compared to other surveys conducted in Brazilian Tropical Forests.
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The patulin, (4hydroxy-4furo[3,2-c]pyran(6H)-1), is a thermal resistent mycotoxin produced by several species of fungi are common in plants, mainly in derivatives and apples. Studies on the toxicity in animals have shown that mycotoxin has character teratogenic, and carcinogenic in mice immunotoxic. Its biosynthesis is well understood involving a series of reactions of condensation and oxiredução, many catalyzed by enzymes. The danger of contamination of food with patulin, warning about the need for a more rigorous control. Recent research aimed their removal and degradation as well as increase the sensitivity of the tests, making them faster and at less cost. The removal of patulin of food is made with composite adsorbents, with inconvenience to diminish the quality of the product by adsorbs other components desirable. The degradation is made with sulfur compounds, which are not allowed in food in many countries, and the growth of yeasts, such as the production of cider. Many yeasts have resistance against patulin and produce compounds capable degrade it. Here, we reviewed research on patulin with emphasis on its influence in food industry, incidence of patulin in apple juice and other foods, maximum permissible concentrations, health effects, biosynthesis, removal, degradation and most widely used methods for its detection and quantification.
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The use of the concept of guild can be useful for the functional trophic categorization of communities, because there is no requirement identification of organisms in the level of species and not to treat each species as a separate entity. The aim of this study was to analyze the functional feeding groups (collectors-gatherers, collectors-filterers, shredders, predators and grazer-scrapers) of the macroinvertebrate communities of two reservoirs in the Midwestern region of São Paulo State. Sampling was carried out in rainy (March/April - 2001) and dry (July/August - 2001) seasons and the data obtained indicate that 'collectors-gatherers' is the most frequent guild. This fact suggests a great importance of organic matter as a food source in the diet of the macroinvertebrates analyzed.